HU182728B - Liquid insecticide containing 0,0-dimethyl-s-/phtalic imido-methyl/-dithiophosphate - Google Patents

Abstract

The present invention relates to a liquid insecticidal composition comprising from 0.5 to 40% by weight of 0.0dimethyl-S- (phthalimido-methyl) dithiophosphate (international free-oscillator), 5-15% surfactants, preferably anionic and \ t nonionic surfactants - and benzene derivatives mono- or di-substituted with 1 to 2 carbon atoms in the range of 55 to 90% by volume, in a ratio of 2.5 to 1: 5: 1, and a dichloromethane solvent mixture. The liquid insecticidal composition of the present invention is both chemically and physically stable. The drug does not show any changes at 50 ° C after 30 days of storage. The emulsion concentrate does not show crystalline precipitation at -5 T after 48 hours of storage, and the aqueous emulsion diluted at 0.5 ° C does not contain crystalline active substance for 24 hours at 20 ° C and the emulsion is stable. -1-

Description

The present invention relates to a liquid insecticide formulation containing 0.0-dimethyl-S- (phthalimidomethyl) -dithiophosphate which contains 0.5 to 40 g / 100 ml of the insecticidal active ingredient in an amount of 5 to 15 g / 100 ml as an emulsifier. a mixture of anionic and nonionic surfactants; and a mixture of 55-90% (v / v) of benzene and dichloromethane substituted with one or two methyl or ethyl groups. The mixture may have a volume ratio of alkylbenzene to dichloromethane in the range of 2.5: 1 to 5 * 1.

The insecticidal activity and preparation of 0.0-dimethyl-S- (phthalimidomethyl) -dl-thiophosphate was first disclosed in U.S. Patent No. 2,776,194. In the early 1960s, U.S. Pat. Its preparation has since been described in several patents / 930,446. USSR patent specification,

No. 157,085 Hungarian patent specification. .

Literature Data / Brown A, W, A: Insect Control by Chemicals. New York. / 1951 / · - Bánki L .: The Effect of Spray Gun. Budapest / 1964/7 the effectiveness and absorption rate of insecticides depends on their formation. Examining the rate of absorption, it has been found that liquid form agents are absorbed into the body of insects at a faster rate than solids / dusting agents, wettable powders, granules / or suspensions. - In line with this, efforts are being made to market pesticides, in particular insecticides, where possible in liquid form.

However, there are several conditions that are difficult to achieve at the same time for the preparation of stable liquid agents. The first of these is to provide an organic, water-immiscible solvent that dissolves the active ingredient sufficiently at both oral and low temperatures (below 0 ° C). In most cases, such a solvent cannot be found and therefore a solution-mediating agent is used.

No. 151,657 is disclosed. According to the Hungarian patent, such a solution-mediated eutectic-forming substance is phenol. Undoubtedly, phenol can be advantageously used for this purpose, but it has the disadvantage of polluting the environment during clio-spraying, and it is undesirable to release it into living waters.

• No. 166.201. According to U.S. Pat. No. 4,677,198, an emulsifiable pest control agent can be prepared by dissolving phosmeth in benzene or toluene with the simultaneous addition of a 1-naphthylamine solution mediator. However, experience has shown that the formulation obtained is chemically unstable, with a longer-term chemical reaction between 0,0-dimethyl-S- (phthalimidomethyl) -dithiophosphate and 1-naphthylamine, leading to conversion / decomposition of the active ingredient. /, reduces the insecticidal effect.

Thus, in order for the selected solvent to meet the requirements, it must be chemically indifferent to the compound to be solubilized, which excludes a significant part of its favorable solubility properties.

In our experiments we examined that the 166,201. The preparation according to Example 2 of the Hungarian patent and the well-known solvents of N-methylpyrrolidone and dimethylformamide known in the literature, which have excellent solubility of the cosmetic, influence the chemical stability of the active ingredient.

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The stability test was carried out using an accelerated procedure *, whereby solutions of 20 g / 100 ml were prepared, the contents of which were accurately determined. The solutions were then stored in a thermostat for 30 days at 50 ° C and subsequently measured for their phosphate content, which demonstrated that a significant proportion of the active ingredient undergoes chemical transformation. - The results of our measurements are shown in Table I.

Table I

solvents gold h.a.% decomposition L-naphthylamine - xylene 1: 4 65.2 N-methylpyrrolidone - 94.0 N-methyl-pyrrolidone-xylene 1: 3 3θ; 2 dimethylformamide - - - 73.6 dimethylformamide - xylene 1: 3 20.3

It can be stated that in all cases the phos- metum is significantly degraded and therefore the nitrogenous solvents or solvent mixtures are not suitable for the preparation of liquid insecticides.

The liquid insecticidal composition must be a system in which the solubility of the phosmet at approximately 20 ° C and -5 ° C is completely chemically indifferent - that is, it does not undergo any chemical change during storage - to form a stable aqueous emulsion. it is easy to emulsify and difficult to break. - However, it is advisable for the liquid preparation to have a closed flash point above 20 ° C.

The difficulty with such formulations is the fact that insecticides are sprayed at a dilution of 0.5%, and the solubility of the otherwise immiscible solvents in water is not negligible at this dilution, which is 0.0-dimethyl-S. results in crystalline precipitation of phthalimidomethyl / dithiophosphorate.

In our research to develop a liquid insecticide composition of the present invention, it has been found that when 0.0-dimethyl-S- / phthalimidomethyl-dithlophosphate is an alkyl benzene solvent and dichloromethane. The solvent is dissolved in a predetermined mixture of the solvent and the appropriate surfactant (s) is added to the solution to give a satisfactory formulation in all respects.

.......... In our research on emulsion concentrate, comparative experiments were conducted with alkylbenzene derivatives and dichloromethane alone and at different tertiary ratios of solvents. the stability of the concentrate.

In each of our experiments, 20 ECs were prepared using the same amounts of surfactants (2 g Atlox 4353 and 8 g Atlox 4857), only solvent quality

-3182.728 ill. the volume ratio of the two solvents in the solvent pair was changed.

When testing the stability of the ernulus concentrate, it was assessed that

- the concentrate shows a precipitation after storage for 48 hours at -5 ° C.

- an aqueous emulsion containing 0.5 to 8% of active ingredient was prepared from machine concentrate with distilled water / after application at this dilution in plant protection / at 20 [deg.] 0 and examined for 24 hrs.

II. spreadsheet

Solvent volume crystal precipitation gold -5 C, 48 hour 0.5% emulsion.20 ° C o-xylene - + 0 o-xylene dichloromethane 10: 1 + 0 o-xiol-di-chloro-methane 5: 1 0 0 o-xylene dichloromethane 4: 1 0 0 o-xylene dichloromethane 3: 1 0 0 o-xylene dichloromethane 2: 1 0 + o-xylene dichloromethane 1: 1 0 + o-xylene dichloromethane 1: 2 0 + - dichloromethane - 0 +

+ mark means crystalline precipitation.

II. Table 2 shows that the emulsion-forming concentrate with either o-xylene or dichloromethane alone does not form a stable solution, but with a 5: 1 and 3: 1 mixture of o-xylene and dichloromethane No precipitation was observed at 0 ° C or in the 0.5% aqueous emulsion. For other solvent ratios, or -500. 0.05-dimethyl-S- (phthalimodomethyl) -dithiophosphate is crystalline in or on 0.5% aqueous emulsion. spreadsheet

Solvent volume gold crystal precipitation -50, 48h 0 , 5 a% egulz. ethylbenzene - + 0 ethylbenzene dichloromethane 10: 1 + 0 ethylbenzene dichloromethane 5: 1 0 0 ethylbenzene dichloromethane 4: 1 0 0 ethylbenzene dichloromethane 3: 1 _ 0 0 ethylbenzene dichloromethane 2: 1 0 + ethylbenzene dichloromethane 1: 1 0 + ethylbenzene dichloromethane 1: 2 0 + -dichloromethane - 0 +

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From the table it can be seen that for the ethylbenzene and dichloromethane solvent range, at a volume ratio of 5: 1-3: 1, 20 EC can be prepared which is neither at -5 ° C nor at 0.5% no crystalline precipitate in aqueous emulsion ·

ARC. spreadsheet

Solvent volume gold crystal -5 ° 0.48 hours 0, secession Emulz.2O ° 5s% O tolu - + 0 toluene-dichloromethane 10x1 + . .......... ........ P toluene-dichloromethane .5x1 0 0 toluene-dichloromethane 4: 1 0 0 toluene-dichloromethane 3x1 0 0 toluene-dichloromethane 2: 1 0 + toluene-dichloromethane 1: 1 0 + toluene-dichloromethane 1: 2 0 + . - dichloromethane - 0 + -; _ t

It is clear from the table that the solvent pair toluene and dichloromethane can be prepared in a stable emulsion concentrate at a volume ratio of 5x1, 4: 1 and 3x1.

It has been found that the volume ratio of alkylbenzene solvent to dichloromethane solvent in the composition can be between 2.5x1 and 5x1.

Alkylbenzene as a solvent may be one. or benzene derivatives substituted with two methyl or ethyl groups such as toluene, ethylbenzene, xylene, but most preferably o-xylene.

The defined ratio of solvent pair according to the invention provides 0.5-40 g / 100 ml of phosphorus in solution at room temperature and low temperature, provides chemical stability and forms a stable aqueous emulsion with surfactants at the desired concentration without - well sprayable. However, the flash point of the liquid preparation is above 20 ° 0 ·

-We examined whether II, III and IV. Table emulsifying agent konaentrátumokban ^ti-1 in a preferred solvent-pair ratios to the active ingredient is chemically much indifferent solvents. After storage for 30 days at 50 ° C, the active ingredient content decreased only by 0.2-0.5% and is thus practically chemically indifferent to the active ingredient phosmet.

- The fact that without the use of a solubilizer, a liquid preparation containing 0.5-40 g / 100 ml of phosphorus, which meets all the quality requirements for these agents, could not have been expected in the literature. "

The liquid insecticide composition of the present invention contains 5-15 g / 100 ml of surfactant as emulsifier fiber along with the active ingredient phosmet and the solvent pair.

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Anionic and nonionic surfactants or mixtures thereof may be used as surfactants; polyoxyethylene alcohols, polyoxyethylene glycerides, pollyloxyethylene alkyl alkyl phenols, polyethylethylene sorbitol esters, dodecylbenzenesulfonic acid calcium salts, and the like. The ratio of anionic to nonionic surfactants can range from 1: 1 to 1: 5.

The liquid insecticide compositions of the present invention are illustrated by the following examples, which are not limited to the claims.

In the examples, Atlas Chemia GmbH. We used surfactants of the company having the following chemical components: Atlox 3400 B: a mixture of calcium salt of dodecylbenzene sulfonic acid and polyoxyethylene / alkyl phenols;

Atlox 4851 B: a mixture of calcium salt of dodecylbenzenesulfonic acid and polyoxyethylene glycerides;

Atlox 4857 B: Mixture of calcium salt of dodecylbenzenesulfonic acid and polyoxyethylene / sorbitol esters, (B denotes B is the biodegradable branch price of the surfactant).

Example 1

To a 500 mL round bottom flask with stirring was added 20 g of 0.0-dimethyl-S- (phthalimidomethyl) dithiophosphate and 57 mL of o-xylene, and after dissolution, 19 mL of dichloromethane was added. Thereafter, 3 g of Atlox 4851 B and 7 g of Atlox 4857 B emulsion were added with constant stirring, after which the solution was filtered to give an emulsion concentrate containing 20% by weight of active ingredient.

Example 2

Into a 500 ml round-bottom flask equipped with a stirrer were weighed 10 g of 0.0-cLimethyl-S- (phthalimidomethyl) -dithiophosphate and 67 ml of o-xylene. then 21 ml of dichloromethane are added with stirring at room temperature. After dissolution, 4 g of Atlox 4857 B and 2 g of Atlox 4851 B are added. After stirring, the solution is filtered to give an emulsion concentrate of 10% w / w.

Example 3

Into a 500 ml round-bottomed flask with a stirrer, weigh 20 g of 0.0-dimethyl-S- (phthalimidomethyl) dithiophosphate, 60 ml of o-xylene and 1? dichloromethane. The mixture was stirred at room temperature until dissolved and then 7 g of Atlox 4857 B and 2 g of Atlox 4851 B were added. After dissolution, the solution is filtered and an emulsion concentrate containing 20% by weight of active ingredient is obtained.

Example 4

A 500 mL round bottom flask with stirring was charged with 17 g of technical (95% purity) 0,0-dimethyl-S- (phthalimidomethyl) -ditlophosphate, 64 mL of xylene and 15 mL of dichloromethane. After dissolution, 7 g of Atlox 4857 B and 2 g of Atlox 3400 B are added with constant stirring, and the solution is then filtered to give an emulsion concentrate of 16 wt%.

Example 5

Into a 500 ml round-bottomed flask with stirring was added 17 g of technical / 94% purity / 0,0-dimethyl-S- / phthalimidomethyl / -6182.728

dithiophosphate, 64 ml ethylbenzene and 15 ml dichloromethane. After dissolution, 2 g of Atlox 3400 B and 7 g of Atlox 4857 B are added. Filtration of the solution yielded an emulsion concentrate containing 16% by weight of the active ingredient.

Example 6

A 500 ml round bottom flask with growth was charged with 23 g of technical (95% purity) O, O-dimethyl-S- (phthalimidomethyl) -dithiophosphate, 60 ml of toluene and 12 ml of dichloromethane. After stirring and dissolving, 6 g of Atlox 4851 B and 6 g of Atlox '4857 B are added, and the solution is filtered.

An emulsion concentrate containing s% trace matter is obtained.

7 »example

Into a 500 mL round bottom flask with stirring was added 30 g of 0.0-dimethyl-3- (phthalimidomethyl) dithiophosphate (47 mL) and 18 mL of dichloromethane. After dissolution, 8 g of Atlox 4851 B and 4 g of Atlox 3400 B are added and the solution is filtered. A liquid insecticide formulation containing 3% of active ingredient is obtained.

Example 8

Into a 500 mL round bottom flask with stirring was added 5 g of 0.0-dimethyl S- (phthalimidomethyl) dithiophosphate, 75 mL of toluene and 15 mL of dichloromethane. After dissolution, 6 g of Atlox 4851 B and 4 g of Atlox 3400 B are added and the solution is filtered. 53% EC was obtained.

The liquid insecticide formulations of the Examples were stored at 50 ° C for> 0 days and were found to have no change in the content of 0 * O-dimethyl-S- / phthalimidomethyl / dithlophosphate and thus the chemical stability. - After storing the liquid preparation at -5 ° C, no solid precipitation was observed after storage for forty-eight hours.

An aqueous emulsion prepared by diluting the liquid preparation with a 50 to 100-fold dilution of the liquid formulation was applied after being used in plant protection practice as a 0.2 to 0.5% by weight spray. It has been found that the liquid formulation is very easy to emulsify and that the emulsion prepared therefrom does not show any precipitation of crystalline material for twenty-four hours.

Claims (2)

Patent claims An oil insecticide composition comprising 0.5-40% by weight of 0.0- dimethyl-S- / phthalimidomethyl-dithiophosphate, 5-15-3% surfactants, preferably anionic and nonionic surfactants, characterized in that: Contains a C2-C2 alkyl moiety of mono or di-substituted benzene derivative and dichloromethane in a volume ratio of -90% to 2.5: 1-5: 1. 2. The liquid insecticidal composition according to claim 1, wherein the benzene derivative comprises toluene or ethylbenzene or o-xylene or m-xylene or p-xylene or a mixture of these isomers.